Organometallic polymers have, in addition to the properties possessed by conventional carbon-type polymers, the properties possessed by organometallic complexes, and they are expected to have new properties that will arise from combinations of a carbon-type polymer and an organometallic complex. Particularly, organometallic polymers are noticeable as electronic materials and nonlinear optical materials. Hitherto, various organometallic polymers have been known (e.g., Polymers, 42, 572 (1993); and J. Am. Chem. Soc., 115, 7035 (1993)). However, organoplatinum polymer containing .pi.-coordinated acetylene in the main chain, and a method for producing the same, are not yet known.